#include <stdio.h>
#include <unistd.h>
#include <signal.h>

void handler (int n) {}
int main (void)
{
	signal (SIGALRM, handler);
	alarm (5);
	int m = pause ();
	//此处的m不能打印, 进程终止了
	printf ("m = %d\n", m);
	return 0;
}
